The present invention relates to a golf training machine and more particularly to a golf swing analyzer for taking an accurate measurement of the swing speed of a golf club and/or for analyzing the swing direction of the golf club. In the conventional swing analyzers, analysis of the swing is effected by detecting points of the output waveforms from sensors at which the waveforms cross a reference potential level, and such analyzers are susceptible to a noise. False operations due to such noise often occur. Then, detection at other different points than the zero crossing of the waveforms so as to get rid of the effects of noise makes it difficult to take correct and exact measurement of speed. Further, the conventional analyzers need at least three separate sensors in order to check the swinging direction.